There is an exhaust heat recovery apparatus for recovering exhaust heat from the internal-combustion engine mounted on a vehicle such as a passenger car, a bus, and a truck by using a thermal engine. As the exhaust heat recovery apparatus used for this purpose, there is a Stirling engine, for example, excellent in theoretical thermal efficiency. Patent Document 1 discloses an apparatus in which a heater of a first Stirling engine and a heater of a second Stirling engine are provided in a passage of exhaust gas exhausted from an internal-combustion engine, the first Stirling engine is disposed on a downstream side of an exhaust gas purification catalyst, and the second Stirling engine is disposed on an upstream side of the exhaust gas purification catalyst.
Patent Document 1: Japanese Patent Application Laid-open No. 2007-187139